The resurgence of measles has led to a fiery debate over whether parents have a right to opt out of vaccinating their children, even if other children or classmates could be at risk.

Measles, a childhood infection caused by a virus, was once common but just about disappeared in the United States due to the MMR – measles, mumps and rubella – vaccine.

Measles is a highly contagious respiratory disease caused by the measles virus. The disease is also called rubeola. Measles causes fever, runny nose, cough and a rash all over the body. About one out of 10 children with measles also gets an ear infection, and up to one out of 20 gets pneumonia. For every 1,000 children who get measles, one or two will die. Adults can also get measles especially if they are not vaccinated. Children under 5 years of age and adults over 20 are at higher risk for measles complications including pneumonia, and a higher risk of hospitalization and death from measles than school aged children and adolescents. (CDC)

Credit: Maureen Downey

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Credit: Maureen Downey

Now, 102 cases have been reported in an outbreak traced to exposure at Disney California Adventure Park in Anaheim, Calif.  The disease spread to other states as the affected Disney visitors returned to their hometowns, schools and workplaces.

Highly contagious, the disease can be fatal in young children . Measles kills more than 100,000 people worldwide each year, most under the age 5.

Schools have been used to press compliance with the strong medical recommendation that all children be vaccinated. Children entering kindergarten are required to show proof they were vaccinated against measles, mumps, rubella, chickenpox, diphtheria, tetanus and whooping cough. In 2013, at least 94 percent of Georgia kindergartners were fully vaccinated.

Georgia parents can opt out of vaccinations by submitting a statement that vaccinations conflict with their religious beliefs or having a doctor certify that one or more vaccines would hurt the child's health.

An AJC story today reported:

In the 14 states now reporting measles cases, some school and public health authorities are taking strong measures. Vaccination campaigns are under way. Some states are publishing school vaccination data, so parents can know the risk. Unvaccinated children are being told they will be barred from school for 21 days if any case of measles is found in their schools. Parents are being told to keep infants, who are too young to be vaccinated, out of crowded areas.

The AJC delved into vaccinations in October with a package featuring an investigation by education writer Molly Bloom and a  searchable database of vaccination rates by school.

Bloom  wrote a detailed story that is worth reading now in light of the concerns over the measles outbreak.

Here is an excerpt of her investigation:

But when data shows high rates of students who are not fully vaccinated or of parents opting their children out of vaccinations, the Georgia Department of Public Health doesn't take key steps that could prevent outbreaks, the AJC found.

It doesn't check the numbers. It doesn't focus education or vaccination programs at the schools. And not once in the past 10 years has it taken legal action to prevent or stop potential violations of state vaccination laws. Nor does it check that, during an outbreak, unvaccinated children are kept out of school, as the law allows.

Other states have taken strong measures to prevent contagious diseases. After a 2010 pertussis, or whooping cough, outbreak in California, linked to more than 9,000 illnesses and 10 deaths, that state passed a law generally requiring a doctor's signature before parents opt out of vaccinations. Washington and Oregon have similar laws, prompted in part by concerns about anti-vaccine misinformation and rising opt-outs. In Colorado, the governor in May signed a bill requiring schools to provide information about vaccination and exemption rates upon request.

About 18 states publish information online about rates at local schools, giving parents information to help them understand the risks for their children and the potential for outbreaks. Georgia does not.

Unvaccinated children aren't the only ones at risk, experts say. So, too, are others who come into contact with students --- like infants or grandparents. Even vaccinated children can become ill since some vaccines don't always fully protect against disease."Even if you do the right thing and get your child vaccinated with a vaccine with 80 percent efficacy, there's a 1 in 5 chance that your child could still get infected," said Saad Omer, an associate professor in Emory University's Rollins School of Public Health.

Debbie Parsons' son, Brandon, caught whooping cough five years ago, even though he had been vaccinated. Brandon, then a fifth-grader at Rocky Mount Elementary School in Cobb County, was a few months short of receiving a booster shot when he first started showing symptoms. For months, he had a cough that at times took his breath away.

Brandon was one of at least 18 students affected by the 2009 outbreak, many of whom had been vaccinated. Parsons said the disease was "a nightmare."

"It's very scary, especially because it's breathing," she said. "You're scared to go to sleep at night because what if you miss something?"

Three years later, Parsons' daughter, Katie, also caught whooping cough---also while in fifth grade. Katie has a genetic condition that makes it harder for her body to fight off disease, but like her brother had been vaccinated. It took her months to recover, and battling whooping cough affected her blood system, heart and overall functioning, Parsons said.

"Your body is trying to fight something that it already doesn't have the energy to fight as it is," she said.

The experience changed her mind about parents who decide not to vaccinate and don't have a medical exemption. While it didn't previously bother her, now it does because she believes it puts her children --- and other children --- at risk.

A poll released Monday found physicians believe the likely sources of the current measles outbreak are unvaccinated children:

-92 percent think the current measles outbreak was directly attributable to parents not vaccinating their children (3,099 respondents)

-79 percent of physicians felt that unvaccinated children, without a medical reason, should not be allowed to attend public schools (3,114 respondents)

The controversy has entered the political arena with potential GOP presidential candidate and New Jersey Gov. Chris Christie saying Monday during a visit to Britain that parents should have some choice on whether to vaccinate their children. (In a quick attempt at damage control, Christie’s office issued a followup statement saying the governor believes "with a disease like measles there is no question kids should be vaccinated.")

Over the weekend, President Barack Obama told NBC News all parents should get their kids vaccinated.

What do you think? Given the risk to others, should vaccines be mandated with few exceptions?

And should schools toughen their stance?